Many of the exploration and development theories derived for conventional clastic rock reservoirs are not applicable to pore-fracture lacustrine carbonate reservoirs. The fluid flow mechanisms under reservoir conditions are still unclear. Therefore, in this study, the rock samples were characterized using X-ray diffraction (XRD), porosity-permeability analysis, scanning electron microscopy (SEM), plain thin sections, and casting thin sections. The core samples were classified into two types (fractures and matrix pores) based on their reservoir spaces. The core flow experiments were performed under reservoir conditions using reservoir core plugs. The experimental results demonstrate that the cores, especially the fractured cores, have a strong stress sensitivity. The oil phase flow in the core has the characteristics of non-Darcy flow, and the threshold pressure gradient is 0.01–0.003 MPa/m. Additionally, for the oil-water two-phase flow in the fractured core, the water phase relative permeability of the residual oil is high. In contrast, the water phase relative permeability of the matrix core is less than 0.2. The nuclear magnetic resonance (NMR) transverse relaxation time (
T
2
) spectra were used to analyze the differences between the water flooding characteristics of the two pore structures. The experimental results show that the peaks of the
T
2
spectra after water flooding are lower than those before water flooding, and the matrix cores have a better oil displacement effect. The relaxation time of 0.1–10 ms makes the greatest contribution to the water flooding efficiency. The micropores smaller than 10 μm in diameter play an important role in the water flooding of the matrix core. These results will provide theoretical basis for solving the difficult problems of developing deep lacustrine carbonate reservoirs.
The effect of irradiation temperature on the microstructure, hardness, and corrosion resistance of 316L stainless steels (SS) fabricated by the selective laser melting (SLM) process was investigated to further understand the radiation degradation of the additive manufactured steels. The Transmission Electron Microscopy (TEM) results confirmed the cellular sub-grains and the high-density dislocation networks present in the SLM formed 316L SS. After exposing samples to Fe11+ ions irradiation till 1 dpa at room temperature, the ultra-fine sub-grain structure maintains its configuration, but the dislocations were observed expanding from the vicinity of the sub-grain boundaries into the grains. In contrast, the expanding phenomenon of dislocations was insignificant in samples irradiated at 450 °C. The average size of dislocation loops increased from 6 to 8.5 nm when the irradiation temperature increased, with the number density decreased from 2.7 × 1022/m3 to 1.3 × 1022/m3. This study reveals that the reduced dislocation loop density and distribution region caused by the improved temperature will suppress the radiation hardening and corrosion of SLM 316L SSs.
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